xref: /openbmc/linux/drivers/mtd/nand/raw/s3c2410.c (revision cabce92d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright © 2004-2008 Simtec Electronics
4  *	http://armlinux.simtec.co.uk/
5  *	Ben Dooks <ben@simtec.co.uk>
6  *
7  * Samsung S3C2410/S3C2440/S3C2412 NAND driver
8 */
9 
10 #define pr_fmt(fmt) "nand-s3c2410: " fmt
11 
12 #ifdef CONFIG_MTD_NAND_S3C2410_DEBUG
13 #define DEBUG
14 #endif
15 
16 #include <linux/module.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/string.h>
20 #include <linux/io.h>
21 #include <linux/ioport.h>
22 #include <linux/platform_device.h>
23 #include <linux/delay.h>
24 #include <linux/err.h>
25 #include <linux/slab.h>
26 #include <linux/clk.h>
27 #include <linux/cpufreq.h>
28 #include <linux/of.h>
29 #include <linux/of_device.h>
30 
31 #include <linux/mtd/mtd.h>
32 #include <linux/mtd/rawnand.h>
33 #include <linux/mtd/partitions.h>
34 
35 #include <linux/platform_data/mtd-nand-s3c2410.h>
36 
37 #define S3C2410_NFREG(x) (x)
38 
39 #define S3C2410_NFCONF		S3C2410_NFREG(0x00)
40 #define S3C2410_NFCMD		S3C2410_NFREG(0x04)
41 #define S3C2410_NFADDR		S3C2410_NFREG(0x08)
42 #define S3C2410_NFDATA		S3C2410_NFREG(0x0C)
43 #define S3C2410_NFSTAT		S3C2410_NFREG(0x10)
44 #define S3C2410_NFECC		S3C2410_NFREG(0x14)
45 #define S3C2440_NFCONT		S3C2410_NFREG(0x04)
46 #define S3C2440_NFCMD		S3C2410_NFREG(0x08)
47 #define S3C2440_NFADDR		S3C2410_NFREG(0x0C)
48 #define S3C2440_NFDATA		S3C2410_NFREG(0x10)
49 #define S3C2440_NFSTAT		S3C2410_NFREG(0x20)
50 #define S3C2440_NFMECC0		S3C2410_NFREG(0x2C)
51 #define S3C2412_NFSTAT		S3C2410_NFREG(0x28)
52 #define S3C2412_NFMECC0		S3C2410_NFREG(0x34)
53 #define S3C2410_NFCONF_EN		(1<<15)
54 #define S3C2410_NFCONF_INITECC		(1<<12)
55 #define S3C2410_NFCONF_nFCE		(1<<11)
56 #define S3C2410_NFCONF_TACLS(x)		((x)<<8)
57 #define S3C2410_NFCONF_TWRPH0(x)	((x)<<4)
58 #define S3C2410_NFCONF_TWRPH1(x)	((x)<<0)
59 #define S3C2410_NFSTAT_BUSY		(1<<0)
60 #define S3C2440_NFCONF_TACLS(x)		((x)<<12)
61 #define S3C2440_NFCONF_TWRPH0(x)	((x)<<8)
62 #define S3C2440_NFCONF_TWRPH1(x)	((x)<<4)
63 #define S3C2440_NFCONT_INITECC		(1<<4)
64 #define S3C2440_NFCONT_nFCE		(1<<1)
65 #define S3C2440_NFCONT_ENABLE		(1<<0)
66 #define S3C2440_NFSTAT_READY		(1<<0)
67 #define S3C2412_NFCONF_NANDBOOT		(1<<31)
68 #define S3C2412_NFCONT_INIT_MAIN_ECC	(1<<5)
69 #define S3C2412_NFCONT_nFCE0		(1<<1)
70 #define S3C2412_NFSTAT_READY		(1<<0)
71 
72 /* new oob placement block for use with hardware ecc generation
73  */
74 static int s3c2410_ooblayout_ecc(struct mtd_info *mtd, int section,
75 				 struct mtd_oob_region *oobregion)
76 {
77 	if (section)
78 		return -ERANGE;
79 
80 	oobregion->offset = 0;
81 	oobregion->length = 3;
82 
83 	return 0;
84 }
85 
86 static int s3c2410_ooblayout_free(struct mtd_info *mtd, int section,
87 				  struct mtd_oob_region *oobregion)
88 {
89 	if (section)
90 		return -ERANGE;
91 
92 	oobregion->offset = 8;
93 	oobregion->length = 8;
94 
95 	return 0;
96 }
97 
98 static const struct mtd_ooblayout_ops s3c2410_ooblayout_ops = {
99 	.ecc = s3c2410_ooblayout_ecc,
100 	.free = s3c2410_ooblayout_free,
101 };
102 
103 /* controller and mtd information */
104 
105 struct s3c2410_nand_info;
106 
107 /**
108  * struct s3c2410_nand_mtd - driver MTD structure
109  * @mtd: The MTD instance to pass to the MTD layer.
110  * @chip: The NAND chip information.
111  * @set: The platform information supplied for this set of NAND chips.
112  * @info: Link back to the hardware information.
113 */
114 struct s3c2410_nand_mtd {
115 	struct nand_chip		chip;
116 	struct s3c2410_nand_set		*set;
117 	struct s3c2410_nand_info	*info;
118 };
119 
120 enum s3c_cpu_type {
121 	TYPE_S3C2410,
122 	TYPE_S3C2412,
123 	TYPE_S3C2440,
124 };
125 
126 enum s3c_nand_clk_state {
127 	CLOCK_DISABLE	= 0,
128 	CLOCK_ENABLE,
129 	CLOCK_SUSPEND,
130 };
131 
132 /* overview of the s3c2410 nand state */
133 
134 /**
135  * struct s3c2410_nand_info - NAND controller state.
136  * @controller: Base controller structure.
137  * @mtds: An array of MTD instances on this controller.
138  * @platform: The platform data for this board.
139  * @device: The platform device we bound to.
140  * @clk: The clock resource for this controller.
141  * @regs: The area mapped for the hardware registers.
142  * @sel_reg: Pointer to the register controlling the NAND selection.
143  * @sel_bit: The bit in @sel_reg to select the NAND chip.
144  * @mtd_count: The number of MTDs created from this controller.
145  * @save_sel: The contents of @sel_reg to be saved over suspend.
146  * @clk_rate: The clock rate from @clk.
147  * @clk_state: The current clock state.
148  * @cpu_type: The exact type of this controller.
149  * @freq_transition: CPUFreq notifier block
150  */
151 struct s3c2410_nand_info {
152 	/* mtd info */
153 	struct nand_controller		controller;
154 	struct s3c2410_nand_mtd		*mtds;
155 	struct s3c2410_platform_nand	*platform;
156 
157 	/* device info */
158 	struct device			*device;
159 	struct clk			*clk;
160 	void __iomem			*regs;
161 	void __iomem			*sel_reg;
162 	int				sel_bit;
163 	int				mtd_count;
164 	unsigned long			save_sel;
165 	unsigned long			clk_rate;
166 	enum s3c_nand_clk_state		clk_state;
167 
168 	enum s3c_cpu_type		cpu_type;
169 };
170 
171 struct s3c24XX_nand_devtype_data {
172 	enum s3c_cpu_type type;
173 };
174 
175 static const struct s3c24XX_nand_devtype_data s3c2410_nand_devtype_data = {
176 	.type = TYPE_S3C2410,
177 };
178 
179 static const struct s3c24XX_nand_devtype_data s3c2412_nand_devtype_data = {
180 	.type = TYPE_S3C2412,
181 };
182 
183 static const struct s3c24XX_nand_devtype_data s3c2440_nand_devtype_data = {
184 	.type = TYPE_S3C2440,
185 };
186 
187 /* conversion functions */
188 
189 static struct s3c2410_nand_mtd *s3c2410_nand_mtd_toours(struct mtd_info *mtd)
190 {
191 	return container_of(mtd_to_nand(mtd), struct s3c2410_nand_mtd,
192 			    chip);
193 }
194 
195 static struct s3c2410_nand_info *s3c2410_nand_mtd_toinfo(struct mtd_info *mtd)
196 {
197 	return s3c2410_nand_mtd_toours(mtd)->info;
198 }
199 
200 static struct s3c2410_nand_info *to_nand_info(struct platform_device *dev)
201 {
202 	return platform_get_drvdata(dev);
203 }
204 
205 static struct s3c2410_platform_nand *to_nand_plat(struct platform_device *dev)
206 {
207 	return dev_get_platdata(&dev->dev);
208 }
209 
210 static inline int allow_clk_suspend(struct s3c2410_nand_info *info)
211 {
212 #ifdef CONFIG_MTD_NAND_S3C2410_CLKSTOP
213 	return 1;
214 #else
215 	return 0;
216 #endif
217 }
218 
219 /**
220  * s3c2410_nand_clk_set_state - Enable, disable or suspend NAND clock.
221  * @info: The controller instance.
222  * @new_state: State to which clock should be set.
223  */
224 static void s3c2410_nand_clk_set_state(struct s3c2410_nand_info *info,
225 		enum s3c_nand_clk_state new_state)
226 {
227 	if (!allow_clk_suspend(info) && new_state == CLOCK_SUSPEND)
228 		return;
229 
230 	if (info->clk_state == CLOCK_ENABLE) {
231 		if (new_state != CLOCK_ENABLE)
232 			clk_disable_unprepare(info->clk);
233 	} else {
234 		if (new_state == CLOCK_ENABLE)
235 			clk_prepare_enable(info->clk);
236 	}
237 
238 	info->clk_state = new_state;
239 }
240 
241 /* timing calculations */
242 
243 #define NS_IN_KHZ 1000000
244 
245 /**
246  * s3c_nand_calc_rate - calculate timing data.
247  * @wanted: The cycle time in nanoseconds.
248  * @clk: The clock rate in kHz.
249  * @max: The maximum divider value.
250  *
251  * Calculate the timing value from the given parameters.
252  */
253 static int s3c_nand_calc_rate(int wanted, unsigned long clk, int max)
254 {
255 	int result;
256 
257 	result = DIV_ROUND_UP((wanted * clk), NS_IN_KHZ);
258 
259 	pr_debug("result %d from %ld, %d\n", result, clk, wanted);
260 
261 	if (result > max) {
262 		pr_err("%d ns is too big for current clock rate %ld\n",
263 			wanted, clk);
264 		return -1;
265 	}
266 
267 	if (result < 1)
268 		result = 1;
269 
270 	return result;
271 }
272 
273 #define to_ns(ticks, clk) (((ticks) * NS_IN_KHZ) / (unsigned int)(clk))
274 
275 /* controller setup */
276 
277 /**
278  * s3c2410_nand_setrate - setup controller timing information.
279  * @info: The controller instance.
280  *
281  * Given the information supplied by the platform, calculate and set
282  * the necessary timing registers in the hardware to generate the
283  * necessary timing cycles to the hardware.
284  */
285 static int s3c2410_nand_setrate(struct s3c2410_nand_info *info)
286 {
287 	struct s3c2410_platform_nand *plat = info->platform;
288 	int tacls_max = (info->cpu_type == TYPE_S3C2412) ? 8 : 4;
289 	int tacls, twrph0, twrph1;
290 	unsigned long clkrate = clk_get_rate(info->clk);
291 	unsigned long set, cfg, mask;
292 	unsigned long flags;
293 
294 	/* calculate the timing information for the controller */
295 
296 	info->clk_rate = clkrate;
297 	clkrate /= 1000;	/* turn clock into kHz for ease of use */
298 
299 	if (plat != NULL) {
300 		tacls = s3c_nand_calc_rate(plat->tacls, clkrate, tacls_max);
301 		twrph0 = s3c_nand_calc_rate(plat->twrph0, clkrate, 8);
302 		twrph1 = s3c_nand_calc_rate(plat->twrph1, clkrate, 8);
303 	} else {
304 		/* default timings */
305 		tacls = tacls_max;
306 		twrph0 = 8;
307 		twrph1 = 8;
308 	}
309 
310 	if (tacls < 0 || twrph0 < 0 || twrph1 < 0) {
311 		dev_err(info->device, "cannot get suitable timings\n");
312 		return -EINVAL;
313 	}
314 
315 	dev_info(info->device, "Tacls=%d, %dns Twrph0=%d %dns, Twrph1=%d %dns\n",
316 		tacls, to_ns(tacls, clkrate), twrph0, to_ns(twrph0, clkrate),
317 						twrph1, to_ns(twrph1, clkrate));
318 
319 	switch (info->cpu_type) {
320 	case TYPE_S3C2410:
321 		mask = (S3C2410_NFCONF_TACLS(3) |
322 			S3C2410_NFCONF_TWRPH0(7) |
323 			S3C2410_NFCONF_TWRPH1(7));
324 		set = S3C2410_NFCONF_EN;
325 		set |= S3C2410_NFCONF_TACLS(tacls - 1);
326 		set |= S3C2410_NFCONF_TWRPH0(twrph0 - 1);
327 		set |= S3C2410_NFCONF_TWRPH1(twrph1 - 1);
328 		break;
329 
330 	case TYPE_S3C2440:
331 	case TYPE_S3C2412:
332 		mask = (S3C2440_NFCONF_TACLS(tacls_max - 1) |
333 			S3C2440_NFCONF_TWRPH0(7) |
334 			S3C2440_NFCONF_TWRPH1(7));
335 
336 		set = S3C2440_NFCONF_TACLS(tacls - 1);
337 		set |= S3C2440_NFCONF_TWRPH0(twrph0 - 1);
338 		set |= S3C2440_NFCONF_TWRPH1(twrph1 - 1);
339 		break;
340 
341 	default:
342 		BUG();
343 	}
344 
345 	local_irq_save(flags);
346 
347 	cfg = readl(info->regs + S3C2410_NFCONF);
348 	cfg &= ~mask;
349 	cfg |= set;
350 	writel(cfg, info->regs + S3C2410_NFCONF);
351 
352 	local_irq_restore(flags);
353 
354 	dev_dbg(info->device, "NF_CONF is 0x%lx\n", cfg);
355 
356 	return 0;
357 }
358 
359 /**
360  * s3c2410_nand_inithw - basic hardware initialisation
361  * @info: The hardware state.
362  *
363  * Do the basic initialisation of the hardware, using s3c2410_nand_setrate()
364  * to setup the hardware access speeds and set the controller to be enabled.
365 */
366 static int s3c2410_nand_inithw(struct s3c2410_nand_info *info)
367 {
368 	int ret;
369 
370 	ret = s3c2410_nand_setrate(info);
371 	if (ret < 0)
372 		return ret;
373 
374 	switch (info->cpu_type) {
375 	case TYPE_S3C2410:
376 	default:
377 		break;
378 
379 	case TYPE_S3C2440:
380 	case TYPE_S3C2412:
381 		/* enable the controller and de-assert nFCE */
382 
383 		writel(S3C2440_NFCONT_ENABLE, info->regs + S3C2440_NFCONT);
384 	}
385 
386 	return 0;
387 }
388 
389 /**
390  * s3c2410_nand_select_chip - select the given nand chip
391  * @this: NAND chip object.
392  * @chip: The chip number.
393  *
394  * This is called by the MTD layer to either select a given chip for the
395  * @mtd instance, or to indicate that the access has finished and the
396  * chip can be de-selected.
397  *
398  * The routine ensures that the nFCE line is correctly setup, and any
399  * platform specific selection code is called to route nFCE to the specific
400  * chip.
401  */
402 static void s3c2410_nand_select_chip(struct nand_chip *this, int chip)
403 {
404 	struct s3c2410_nand_info *info;
405 	struct s3c2410_nand_mtd *nmtd;
406 	unsigned long cur;
407 
408 	nmtd = nand_get_controller_data(this);
409 	info = nmtd->info;
410 
411 	if (chip != -1)
412 		s3c2410_nand_clk_set_state(info, CLOCK_ENABLE);
413 
414 	cur = readl(info->sel_reg);
415 
416 	if (chip == -1) {
417 		cur |= info->sel_bit;
418 	} else {
419 		if (nmtd->set != NULL && chip > nmtd->set->nr_chips) {
420 			dev_err(info->device, "invalid chip %d\n", chip);
421 			return;
422 		}
423 
424 		if (info->platform != NULL) {
425 			if (info->platform->select_chip != NULL)
426 				(info->platform->select_chip) (nmtd->set, chip);
427 		}
428 
429 		cur &= ~info->sel_bit;
430 	}
431 
432 	writel(cur, info->sel_reg);
433 
434 	if (chip == -1)
435 		s3c2410_nand_clk_set_state(info, CLOCK_SUSPEND);
436 }
437 
438 /* s3c2410_nand_hwcontrol
439  *
440  * Issue command and address cycles to the chip
441 */
442 
443 static void s3c2410_nand_hwcontrol(struct nand_chip *chip, int cmd,
444 				   unsigned int ctrl)
445 {
446 	struct mtd_info *mtd = nand_to_mtd(chip);
447 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
448 
449 	if (cmd == NAND_CMD_NONE)
450 		return;
451 
452 	if (ctrl & NAND_CLE)
453 		writeb(cmd, info->regs + S3C2410_NFCMD);
454 	else
455 		writeb(cmd, info->regs + S3C2410_NFADDR);
456 }
457 
458 /* command and control functions */
459 
460 static void s3c2440_nand_hwcontrol(struct nand_chip *chip, int cmd,
461 				   unsigned int ctrl)
462 {
463 	struct mtd_info *mtd = nand_to_mtd(chip);
464 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
465 
466 	if (cmd == NAND_CMD_NONE)
467 		return;
468 
469 	if (ctrl & NAND_CLE)
470 		writeb(cmd, info->regs + S3C2440_NFCMD);
471 	else
472 		writeb(cmd, info->regs + S3C2440_NFADDR);
473 }
474 
475 /* s3c2410_nand_devready()
476  *
477  * returns 0 if the nand is busy, 1 if it is ready
478 */
479 
480 static int s3c2410_nand_devready(struct nand_chip *chip)
481 {
482 	struct mtd_info *mtd = nand_to_mtd(chip);
483 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
484 	return readb(info->regs + S3C2410_NFSTAT) & S3C2410_NFSTAT_BUSY;
485 }
486 
487 static int s3c2440_nand_devready(struct nand_chip *chip)
488 {
489 	struct mtd_info *mtd = nand_to_mtd(chip);
490 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
491 	return readb(info->regs + S3C2440_NFSTAT) & S3C2440_NFSTAT_READY;
492 }
493 
494 static int s3c2412_nand_devready(struct nand_chip *chip)
495 {
496 	struct mtd_info *mtd = nand_to_mtd(chip);
497 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
498 	return readb(info->regs + S3C2412_NFSTAT) & S3C2412_NFSTAT_READY;
499 }
500 
501 /* ECC handling functions */
502 
503 static int s3c2410_nand_correct_data(struct nand_chip *chip, u_char *dat,
504 				     u_char *read_ecc, u_char *calc_ecc)
505 {
506 	struct mtd_info *mtd = nand_to_mtd(chip);
507 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
508 	unsigned int diff0, diff1, diff2;
509 	unsigned int bit, byte;
510 
511 	pr_debug("%s(%p,%p,%p,%p)\n", __func__, mtd, dat, read_ecc, calc_ecc);
512 
513 	diff0 = read_ecc[0] ^ calc_ecc[0];
514 	diff1 = read_ecc[1] ^ calc_ecc[1];
515 	diff2 = read_ecc[2] ^ calc_ecc[2];
516 
517 	pr_debug("%s: rd %*phN calc %*phN diff %02x%02x%02x\n",
518 		 __func__, 3, read_ecc, 3, calc_ecc,
519 		 diff0, diff1, diff2);
520 
521 	if (diff0 == 0 && diff1 == 0 && diff2 == 0)
522 		return 0;		/* ECC is ok */
523 
524 	/* sometimes people do not think about using the ECC, so check
525 	 * to see if we have an 0xff,0xff,0xff read ECC and then ignore
526 	 * the error, on the assumption that this is an un-eccd page.
527 	 */
528 	if (read_ecc[0] == 0xff && read_ecc[1] == 0xff && read_ecc[2] == 0xff
529 	    && info->platform->ignore_unset_ecc)
530 		return 0;
531 
532 	/* Can we correct this ECC (ie, one row and column change).
533 	 * Note, this is similar to the 256 error code on smartmedia */
534 
535 	if (((diff0 ^ (diff0 >> 1)) & 0x55) == 0x55 &&
536 	    ((diff1 ^ (diff1 >> 1)) & 0x55) == 0x55 &&
537 	    ((diff2 ^ (diff2 >> 1)) & 0x55) == 0x55) {
538 		/* calculate the bit position of the error */
539 
540 		bit  = ((diff2 >> 3) & 1) |
541 		       ((diff2 >> 4) & 2) |
542 		       ((diff2 >> 5) & 4);
543 
544 		/* calculate the byte position of the error */
545 
546 		byte = ((diff2 << 7) & 0x100) |
547 		       ((diff1 << 0) & 0x80)  |
548 		       ((diff1 << 1) & 0x40)  |
549 		       ((diff1 << 2) & 0x20)  |
550 		       ((diff1 << 3) & 0x10)  |
551 		       ((diff0 >> 4) & 0x08)  |
552 		       ((diff0 >> 3) & 0x04)  |
553 		       ((diff0 >> 2) & 0x02)  |
554 		       ((diff0 >> 1) & 0x01);
555 
556 		dev_dbg(info->device, "correcting error bit %d, byte %d\n",
557 			bit, byte);
558 
559 		dat[byte] ^= (1 << bit);
560 		return 1;
561 	}
562 
563 	/* if there is only one bit difference in the ECC, then
564 	 * one of only a row or column parity has changed, which
565 	 * means the error is most probably in the ECC itself */
566 
567 	diff0 |= (diff1 << 8);
568 	diff0 |= (diff2 << 16);
569 
570 	/* equal to "(diff0 & ~(1 << __ffs(diff0)))" */
571 	if ((diff0 & (diff0 - 1)) == 0)
572 		return 1;
573 
574 	return -1;
575 }
576 
577 /* ECC functions
578  *
579  * These allow the s3c2410 and s3c2440 to use the controller's ECC
580  * generator block to ECC the data as it passes through]
581 */
582 
583 static void s3c2410_nand_enable_hwecc(struct nand_chip *chip, int mode)
584 {
585 	struct s3c2410_nand_info *info;
586 	unsigned long ctrl;
587 
588 	info = s3c2410_nand_mtd_toinfo(nand_to_mtd(chip));
589 	ctrl = readl(info->regs + S3C2410_NFCONF);
590 	ctrl |= S3C2410_NFCONF_INITECC;
591 	writel(ctrl, info->regs + S3C2410_NFCONF);
592 }
593 
594 static void s3c2412_nand_enable_hwecc(struct nand_chip *chip, int mode)
595 {
596 	struct s3c2410_nand_info *info;
597 	unsigned long ctrl;
598 
599 	info = s3c2410_nand_mtd_toinfo(nand_to_mtd(chip));
600 	ctrl = readl(info->regs + S3C2440_NFCONT);
601 	writel(ctrl | S3C2412_NFCONT_INIT_MAIN_ECC,
602 	       info->regs + S3C2440_NFCONT);
603 }
604 
605 static void s3c2440_nand_enable_hwecc(struct nand_chip *chip, int mode)
606 {
607 	struct s3c2410_nand_info *info;
608 	unsigned long ctrl;
609 
610 	info = s3c2410_nand_mtd_toinfo(nand_to_mtd(chip));
611 	ctrl = readl(info->regs + S3C2440_NFCONT);
612 	writel(ctrl | S3C2440_NFCONT_INITECC, info->regs + S3C2440_NFCONT);
613 }
614 
615 static int s3c2410_nand_calculate_ecc(struct nand_chip *chip,
616 				      const u_char *dat, u_char *ecc_code)
617 {
618 	struct mtd_info *mtd = nand_to_mtd(chip);
619 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
620 
621 	ecc_code[0] = readb(info->regs + S3C2410_NFECC + 0);
622 	ecc_code[1] = readb(info->regs + S3C2410_NFECC + 1);
623 	ecc_code[2] = readb(info->regs + S3C2410_NFECC + 2);
624 
625 	pr_debug("%s: returning ecc %*phN\n", __func__, 3, ecc_code);
626 
627 	return 0;
628 }
629 
630 static int s3c2412_nand_calculate_ecc(struct nand_chip *chip,
631 				      const u_char *dat, u_char *ecc_code)
632 {
633 	struct mtd_info *mtd = nand_to_mtd(chip);
634 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
635 	unsigned long ecc = readl(info->regs + S3C2412_NFMECC0);
636 
637 	ecc_code[0] = ecc;
638 	ecc_code[1] = ecc >> 8;
639 	ecc_code[2] = ecc >> 16;
640 
641 	pr_debug("%s: returning ecc %*phN\n", __func__, 3, ecc_code);
642 
643 	return 0;
644 }
645 
646 static int s3c2440_nand_calculate_ecc(struct nand_chip *chip,
647 				      const u_char *dat, u_char *ecc_code)
648 {
649 	struct mtd_info *mtd = nand_to_mtd(chip);
650 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
651 	unsigned long ecc = readl(info->regs + S3C2440_NFMECC0);
652 
653 	ecc_code[0] = ecc;
654 	ecc_code[1] = ecc >> 8;
655 	ecc_code[2] = ecc >> 16;
656 
657 	pr_debug("%s: returning ecc %06lx\n", __func__, ecc & 0xffffff);
658 
659 	return 0;
660 }
661 
662 /* over-ride the standard functions for a little more speed. We can
663  * use read/write block to move the data buffers to/from the controller
664 */
665 
666 static void s3c2410_nand_read_buf(struct nand_chip *this, u_char *buf, int len)
667 {
668 	readsb(this->legacy.IO_ADDR_R, buf, len);
669 }
670 
671 static void s3c2440_nand_read_buf(struct nand_chip *this, u_char *buf, int len)
672 {
673 	struct mtd_info *mtd = nand_to_mtd(this);
674 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
675 
676 	readsl(info->regs + S3C2440_NFDATA, buf, len >> 2);
677 
678 	/* cleanup if we've got less than a word to do */
679 	if (len & 3) {
680 		buf += len & ~3;
681 
682 		for (; len & 3; len--)
683 			*buf++ = readb(info->regs + S3C2440_NFDATA);
684 	}
685 }
686 
687 static void s3c2410_nand_write_buf(struct nand_chip *this, const u_char *buf,
688 				   int len)
689 {
690 	writesb(this->legacy.IO_ADDR_W, buf, len);
691 }
692 
693 static void s3c2440_nand_write_buf(struct nand_chip *this, const u_char *buf,
694 				   int len)
695 {
696 	struct mtd_info *mtd = nand_to_mtd(this);
697 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
698 
699 	writesl(info->regs + S3C2440_NFDATA, buf, len >> 2);
700 
701 	/* cleanup any fractional write */
702 	if (len & 3) {
703 		buf += len & ~3;
704 
705 		for (; len & 3; len--, buf++)
706 			writeb(*buf, info->regs + S3C2440_NFDATA);
707 	}
708 }
709 
710 /* device management functions */
711 
712 static void s3c24xx_nand_remove(struct platform_device *pdev)
713 {
714 	struct s3c2410_nand_info *info = to_nand_info(pdev);
715 
716 	if (info == NULL)
717 		return;
718 
719 	/* Release all our mtds  and their partitions, then go through
720 	 * freeing the resources used
721 	 */
722 
723 	if (info->mtds != NULL) {
724 		struct s3c2410_nand_mtd *ptr = info->mtds;
725 		int mtdno;
726 
727 		for (mtdno = 0; mtdno < info->mtd_count; mtdno++, ptr++) {
728 			pr_debug("releasing mtd %d (%p)\n", mtdno, ptr);
729 			WARN_ON(mtd_device_unregister(nand_to_mtd(&ptr->chip)));
730 			nand_cleanup(&ptr->chip);
731 		}
732 	}
733 
734 	/* free the common resources */
735 
736 	if (!IS_ERR(info->clk))
737 		s3c2410_nand_clk_set_state(info, CLOCK_DISABLE);
738 }
739 
740 static int s3c2410_nand_add_partition(struct s3c2410_nand_info *info,
741 				      struct s3c2410_nand_mtd *mtd,
742 				      struct s3c2410_nand_set *set)
743 {
744 	if (set) {
745 		struct mtd_info *mtdinfo = nand_to_mtd(&mtd->chip);
746 
747 		mtdinfo->name = set->name;
748 
749 		return mtd_device_register(mtdinfo, set->partitions,
750 					   set->nr_partitions);
751 	}
752 
753 	return -ENODEV;
754 }
755 
756 static int s3c2410_nand_setup_interface(struct nand_chip *chip, int csline,
757 					const struct nand_interface_config *conf)
758 {
759 	struct mtd_info *mtd = nand_to_mtd(chip);
760 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
761 	struct s3c2410_platform_nand *pdata = info->platform;
762 	const struct nand_sdr_timings *timings;
763 	int tacls;
764 
765 	timings = nand_get_sdr_timings(conf);
766 	if (IS_ERR(timings))
767 		return -ENOTSUPP;
768 
769 	tacls = timings->tCLS_min - timings->tWP_min;
770 	if (tacls < 0)
771 		tacls = 0;
772 
773 	pdata->tacls  = DIV_ROUND_UP(tacls, 1000);
774 	pdata->twrph0 = DIV_ROUND_UP(timings->tWP_min, 1000);
775 	pdata->twrph1 = DIV_ROUND_UP(timings->tCLH_min, 1000);
776 
777 	return s3c2410_nand_setrate(info);
778 }
779 
780 /**
781  * s3c2410_nand_init_chip - initialise a single instance of an chip
782  * @info: The base NAND controller the chip is on.
783  * @nmtd: The new controller MTD instance to fill in.
784  * @set: The information passed from the board specific platform data.
785  *
786  * Initialise the given @nmtd from the information in @info and @set. This
787  * readies the structure for use with the MTD layer functions by ensuring
788  * all pointers are setup and the necessary control routines selected.
789  */
790 static void s3c2410_nand_init_chip(struct s3c2410_nand_info *info,
791 				   struct s3c2410_nand_mtd *nmtd,
792 				   struct s3c2410_nand_set *set)
793 {
794 	struct device_node *np = info->device->of_node;
795 	struct nand_chip *chip = &nmtd->chip;
796 	void __iomem *regs = info->regs;
797 
798 	nand_set_flash_node(chip, set->of_node);
799 
800 	chip->legacy.write_buf    = s3c2410_nand_write_buf;
801 	chip->legacy.read_buf     = s3c2410_nand_read_buf;
802 	chip->legacy.select_chip  = s3c2410_nand_select_chip;
803 	chip->legacy.chip_delay   = 50;
804 	nand_set_controller_data(chip, nmtd);
805 	chip->options	   = set->options;
806 	chip->controller   = &info->controller;
807 
808 	/*
809 	 * let's keep behavior unchanged for legacy boards booting via pdata and
810 	 * auto-detect timings only when booting with a device tree.
811 	 */
812 	if (!np)
813 		chip->options |= NAND_KEEP_TIMINGS;
814 
815 	switch (info->cpu_type) {
816 	case TYPE_S3C2410:
817 		chip->legacy.IO_ADDR_W = regs + S3C2410_NFDATA;
818 		info->sel_reg   = regs + S3C2410_NFCONF;
819 		info->sel_bit	= S3C2410_NFCONF_nFCE;
820 		chip->legacy.cmd_ctrl  = s3c2410_nand_hwcontrol;
821 		chip->legacy.dev_ready = s3c2410_nand_devready;
822 		break;
823 
824 	case TYPE_S3C2440:
825 		chip->legacy.IO_ADDR_W = regs + S3C2440_NFDATA;
826 		info->sel_reg   = regs + S3C2440_NFCONT;
827 		info->sel_bit	= S3C2440_NFCONT_nFCE;
828 		chip->legacy.cmd_ctrl  = s3c2440_nand_hwcontrol;
829 		chip->legacy.dev_ready = s3c2440_nand_devready;
830 		chip->legacy.read_buf  = s3c2440_nand_read_buf;
831 		chip->legacy.write_buf	= s3c2440_nand_write_buf;
832 		break;
833 
834 	case TYPE_S3C2412:
835 		chip->legacy.IO_ADDR_W = regs + S3C2440_NFDATA;
836 		info->sel_reg   = regs + S3C2440_NFCONT;
837 		info->sel_bit	= S3C2412_NFCONT_nFCE0;
838 		chip->legacy.cmd_ctrl  = s3c2440_nand_hwcontrol;
839 		chip->legacy.dev_ready = s3c2412_nand_devready;
840 
841 		if (readl(regs + S3C2410_NFCONF) & S3C2412_NFCONF_NANDBOOT)
842 			dev_info(info->device, "System booted from NAND\n");
843 
844 		break;
845 	}
846 
847 	chip->legacy.IO_ADDR_R = chip->legacy.IO_ADDR_W;
848 
849 	nmtd->info	   = info;
850 	nmtd->set	   = set;
851 
852 	chip->ecc.engine_type = info->platform->engine_type;
853 
854 	/*
855 	 * If you use u-boot BBT creation code, specifying this flag will
856 	 * let the kernel fish out the BBT from the NAND.
857 	 */
858 	if (set->flash_bbt)
859 		chip->bbt_options |= NAND_BBT_USE_FLASH;
860 }
861 
862 /**
863  * s3c2410_nand_attach_chip - Init the ECC engine after NAND scan
864  * @chip: The NAND chip
865  *
866  * This hook is called by the core after the identification of the NAND chip,
867  * once the relevant per-chip information is up to date.. This call ensure that
868  * we update the internal state accordingly.
869  *
870  * The internal state is currently limited to the ECC state information.
871 */
872 static int s3c2410_nand_attach_chip(struct nand_chip *chip)
873 {
874 	struct mtd_info *mtd = nand_to_mtd(chip);
875 	struct s3c2410_nand_info *info = s3c2410_nand_mtd_toinfo(mtd);
876 
877 	switch (chip->ecc.engine_type) {
878 
879 	case NAND_ECC_ENGINE_TYPE_NONE:
880 		dev_info(info->device, "ECC disabled\n");
881 		break;
882 
883 	case NAND_ECC_ENGINE_TYPE_SOFT:
884 		/*
885 		 * This driver expects Hamming based ECC when engine_type is set
886 		 * to NAND_ECC_ENGINE_TYPE_SOFT. Force ecc.algo to
887 		 * NAND_ECC_ALGO_HAMMING to avoid adding an extra ecc_algo field
888 		 * to s3c2410_platform_nand.
889 		 */
890 		chip->ecc.algo = NAND_ECC_ALGO_HAMMING;
891 		dev_info(info->device, "soft ECC\n");
892 		break;
893 
894 	case NAND_ECC_ENGINE_TYPE_ON_HOST:
895 		chip->ecc.calculate = s3c2410_nand_calculate_ecc;
896 		chip->ecc.correct   = s3c2410_nand_correct_data;
897 		chip->ecc.strength  = 1;
898 
899 		switch (info->cpu_type) {
900 		case TYPE_S3C2410:
901 			chip->ecc.hwctl	    = s3c2410_nand_enable_hwecc;
902 			chip->ecc.calculate = s3c2410_nand_calculate_ecc;
903 			break;
904 
905 		case TYPE_S3C2412:
906 			chip->ecc.hwctl     = s3c2412_nand_enable_hwecc;
907 			chip->ecc.calculate = s3c2412_nand_calculate_ecc;
908 			break;
909 
910 		case TYPE_S3C2440:
911 			chip->ecc.hwctl     = s3c2440_nand_enable_hwecc;
912 			chip->ecc.calculate = s3c2440_nand_calculate_ecc;
913 			break;
914 		}
915 
916 		dev_dbg(info->device, "chip %p => page shift %d\n",
917 			chip, chip->page_shift);
918 
919 		/* change the behaviour depending on whether we are using
920 		 * the large or small page nand device */
921 		if (chip->page_shift > 10) {
922 			chip->ecc.size	    = 256;
923 			chip->ecc.bytes	    = 3;
924 		} else {
925 			chip->ecc.size	    = 512;
926 			chip->ecc.bytes	    = 3;
927 			mtd_set_ooblayout(nand_to_mtd(chip),
928 					  &s3c2410_ooblayout_ops);
929 		}
930 
931 		dev_info(info->device, "hardware ECC\n");
932 		break;
933 
934 	default:
935 		dev_err(info->device, "invalid ECC mode!\n");
936 		return -EINVAL;
937 	}
938 
939 	if (chip->bbt_options & NAND_BBT_USE_FLASH)
940 		chip->options |= NAND_SKIP_BBTSCAN;
941 
942 	return 0;
943 }
944 
945 static const struct nand_controller_ops s3c24xx_nand_controller_ops = {
946 	.attach_chip = s3c2410_nand_attach_chip,
947 	.setup_interface = s3c2410_nand_setup_interface,
948 };
949 
950 static const struct of_device_id s3c24xx_nand_dt_ids[] = {
951 	{
952 		.compatible = "samsung,s3c2410-nand",
953 		.data = &s3c2410_nand_devtype_data,
954 	}, {
955 		/* also compatible with s3c6400 */
956 		.compatible = "samsung,s3c2412-nand",
957 		.data = &s3c2412_nand_devtype_data,
958 	}, {
959 		.compatible = "samsung,s3c2440-nand",
960 		.data = &s3c2440_nand_devtype_data,
961 	},
962 	{ /* sentinel */ }
963 };
964 MODULE_DEVICE_TABLE(of, s3c24xx_nand_dt_ids);
965 
966 static int s3c24xx_nand_probe_dt(struct platform_device *pdev)
967 {
968 	const struct s3c24XX_nand_devtype_data *devtype_data;
969 	struct s3c2410_platform_nand *pdata;
970 	struct s3c2410_nand_info *info = platform_get_drvdata(pdev);
971 	struct device_node *np = pdev->dev.of_node, *child;
972 	struct s3c2410_nand_set *sets;
973 
974 	devtype_data = of_device_get_match_data(&pdev->dev);
975 	if (!devtype_data)
976 		return -ENODEV;
977 
978 	info->cpu_type = devtype_data->type;
979 
980 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
981 	if (!pdata)
982 		return -ENOMEM;
983 
984 	pdev->dev.platform_data = pdata;
985 
986 	pdata->nr_sets = of_get_child_count(np);
987 	if (!pdata->nr_sets)
988 		return 0;
989 
990 	sets = devm_kcalloc(&pdev->dev, pdata->nr_sets, sizeof(*sets),
991 			    GFP_KERNEL);
992 	if (!sets)
993 		return -ENOMEM;
994 
995 	pdata->sets = sets;
996 
997 	for_each_available_child_of_node(np, child) {
998 		sets->name = (char *)child->name;
999 		sets->of_node = child;
1000 		sets->nr_chips = 1;
1001 
1002 		of_node_get(child);
1003 
1004 		sets++;
1005 	}
1006 
1007 	return 0;
1008 }
1009 
1010 static int s3c24xx_nand_probe_pdata(struct platform_device *pdev)
1011 {
1012 	struct s3c2410_nand_info *info = platform_get_drvdata(pdev);
1013 
1014 	info->cpu_type = platform_get_device_id(pdev)->driver_data;
1015 
1016 	return 0;
1017 }
1018 
1019 /* s3c24xx_nand_probe
1020  *
1021  * called by device layer when it finds a device matching
1022  * one our driver can handled. This code checks to see if
1023  * it can allocate all necessary resources then calls the
1024  * nand layer to look for devices
1025 */
1026 static int s3c24xx_nand_probe(struct platform_device *pdev)
1027 {
1028 	struct s3c2410_platform_nand *plat;
1029 	struct s3c2410_nand_info *info;
1030 	struct s3c2410_nand_mtd *nmtd;
1031 	struct s3c2410_nand_set *sets;
1032 	struct resource *res;
1033 	int err = 0;
1034 	int size;
1035 	int nr_sets;
1036 	int setno;
1037 
1038 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
1039 	if (info == NULL) {
1040 		err = -ENOMEM;
1041 		goto exit_error;
1042 	}
1043 
1044 	platform_set_drvdata(pdev, info);
1045 
1046 	nand_controller_init(&info->controller);
1047 	info->controller.ops = &s3c24xx_nand_controller_ops;
1048 
1049 	/* get the clock source and enable it */
1050 
1051 	info->clk = devm_clk_get(&pdev->dev, "nand");
1052 	if (IS_ERR(info->clk)) {
1053 		dev_err(&pdev->dev, "failed to get clock\n");
1054 		err = -ENOENT;
1055 		goto exit_error;
1056 	}
1057 
1058 	s3c2410_nand_clk_set_state(info, CLOCK_ENABLE);
1059 
1060 	if (pdev->dev.of_node)
1061 		err = s3c24xx_nand_probe_dt(pdev);
1062 	else
1063 		err = s3c24xx_nand_probe_pdata(pdev);
1064 
1065 	if (err)
1066 		goto exit_error;
1067 
1068 	plat = to_nand_plat(pdev);
1069 
1070 	/* allocate and map the resource */
1071 
1072 	/* currently we assume we have the one resource */
1073 	res = pdev->resource;
1074 	size = resource_size(res);
1075 
1076 	info->device	= &pdev->dev;
1077 	info->platform	= plat;
1078 
1079 	info->regs = devm_ioremap_resource(&pdev->dev, res);
1080 	if (IS_ERR(info->regs)) {
1081 		err = PTR_ERR(info->regs);
1082 		goto exit_error;
1083 	}
1084 
1085 	dev_dbg(&pdev->dev, "mapped registers at %p\n", info->regs);
1086 
1087 	if (!plat->sets || plat->nr_sets < 1) {
1088 		err = -EINVAL;
1089 		goto exit_error;
1090 	}
1091 
1092 	sets = plat->sets;
1093 	nr_sets = plat->nr_sets;
1094 
1095 	info->mtd_count = nr_sets;
1096 
1097 	/* allocate our information */
1098 
1099 	size = nr_sets * sizeof(*info->mtds);
1100 	info->mtds = devm_kzalloc(&pdev->dev, size, GFP_KERNEL);
1101 	if (info->mtds == NULL) {
1102 		err = -ENOMEM;
1103 		goto exit_error;
1104 	}
1105 
1106 	/* initialise all possible chips */
1107 
1108 	nmtd = info->mtds;
1109 
1110 	for (setno = 0; setno < nr_sets; setno++, nmtd++, sets++) {
1111 		struct mtd_info *mtd = nand_to_mtd(&nmtd->chip);
1112 
1113 		pr_debug("initialising set %d (%p, info %p)\n",
1114 			 setno, nmtd, info);
1115 
1116 		mtd->dev.parent = &pdev->dev;
1117 		s3c2410_nand_init_chip(info, nmtd, sets);
1118 
1119 		err = nand_scan(&nmtd->chip, sets ? sets->nr_chips : 1);
1120 		if (err)
1121 			goto exit_error;
1122 
1123 		s3c2410_nand_add_partition(info, nmtd, sets);
1124 	}
1125 
1126 	/* initialise the hardware */
1127 	err = s3c2410_nand_inithw(info);
1128 	if (err != 0)
1129 		goto exit_error;
1130 
1131 	if (allow_clk_suspend(info)) {
1132 		dev_info(&pdev->dev, "clock idle support enabled\n");
1133 		s3c2410_nand_clk_set_state(info, CLOCK_SUSPEND);
1134 	}
1135 
1136 	return 0;
1137 
1138  exit_error:
1139 	s3c24xx_nand_remove(pdev);
1140 
1141 	if (err == 0)
1142 		err = -EINVAL;
1143 	return err;
1144 }
1145 
1146 /* PM Support */
1147 #ifdef CONFIG_PM
1148 
1149 static int s3c24xx_nand_suspend(struct platform_device *dev, pm_message_t pm)
1150 {
1151 	struct s3c2410_nand_info *info = platform_get_drvdata(dev);
1152 
1153 	if (info) {
1154 		info->save_sel = readl(info->sel_reg);
1155 
1156 		/* For the moment, we must ensure nFCE is high during
1157 		 * the time we are suspended. This really should be
1158 		 * handled by suspending the MTDs we are using, but
1159 		 * that is currently not the case. */
1160 
1161 		writel(info->save_sel | info->sel_bit, info->sel_reg);
1162 
1163 		s3c2410_nand_clk_set_state(info, CLOCK_DISABLE);
1164 	}
1165 
1166 	return 0;
1167 }
1168 
1169 static int s3c24xx_nand_resume(struct platform_device *dev)
1170 {
1171 	struct s3c2410_nand_info *info = platform_get_drvdata(dev);
1172 	unsigned long sel;
1173 
1174 	if (info) {
1175 		s3c2410_nand_clk_set_state(info, CLOCK_ENABLE);
1176 		s3c2410_nand_inithw(info);
1177 
1178 		/* Restore the state of the nFCE line. */
1179 
1180 		sel = readl(info->sel_reg);
1181 		sel &= ~info->sel_bit;
1182 		sel |= info->save_sel & info->sel_bit;
1183 		writel(sel, info->sel_reg);
1184 
1185 		s3c2410_nand_clk_set_state(info, CLOCK_SUSPEND);
1186 	}
1187 
1188 	return 0;
1189 }
1190 
1191 #else
1192 #define s3c24xx_nand_suspend NULL
1193 #define s3c24xx_nand_resume NULL
1194 #endif
1195 
1196 /* driver device registration */
1197 
1198 static const struct platform_device_id s3c24xx_driver_ids[] = {
1199 	{
1200 		.name		= "s3c2410-nand",
1201 		.driver_data	= TYPE_S3C2410,
1202 	}, {
1203 		.name		= "s3c2440-nand",
1204 		.driver_data	= TYPE_S3C2440,
1205 	}, {
1206 		.name		= "s3c2412-nand",
1207 		.driver_data	= TYPE_S3C2412,
1208 	}, {
1209 		.name		= "s3c6400-nand",
1210 		.driver_data	= TYPE_S3C2412, /* compatible with 2412 */
1211 	},
1212 	{ }
1213 };
1214 
1215 MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
1216 
1217 static struct platform_driver s3c24xx_nand_driver = {
1218 	.probe		= s3c24xx_nand_probe,
1219 	.remove_new	= s3c24xx_nand_remove,
1220 	.suspend	= s3c24xx_nand_suspend,
1221 	.resume		= s3c24xx_nand_resume,
1222 	.id_table	= s3c24xx_driver_ids,
1223 	.driver		= {
1224 		.name	= "s3c24xx-nand",
1225 		.of_match_table = s3c24xx_nand_dt_ids,
1226 	},
1227 };
1228 
1229 module_platform_driver(s3c24xx_nand_driver);
1230 
1231 MODULE_LICENSE("GPL");
1232 MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
1233 MODULE_DESCRIPTION("S3C24XX MTD NAND driver");
1234